The Joint Committee on Mental Health, Substance Use and Recovery approved a measure that keeps some of the governor's original proposals, including one that would allow doctors to hold patients for up to three days if their addiction is deemed dangerous.

"This bill highlights the state's commitment and compassion in dealing with the opioid epidemic," said Needham Rep. Denise Garlick, the House chair of the committee.

The 50-page bill also allows emergency rooms to begin medication-assisted treatment, or MAT, after an overdose and sets up several commissions to begin working on prevention and treatment improvement.

Sen. Cynthia Friedman, the Senate chair of the committee, advised Senate members to reserve their rights on the bill, which means they can change their vote when it goes before the full Senate. She is concerned about the logistics of how a patient might be deemed dangerous and held for three days.

"The who, what and where of that is not clear at this point," Friedman said.

Although the legislation establishes a committee to create a new level of treatment for those with both substance use and mental health disorders, Friedman also has concerns about exactly how that will be done.

The bill does not mention two controversial ideas: safe injection sites, where people can use drugs under medical supervision; and MAT for people who are incarcerated. Right now, some Massachusetts prisons only offer one of the three approved forms of addiction medication. The Massachusetts U.S. attorney is reviewing that issue to determine if it's a violation of federal law to deny all forms of the medication to those incarcerated.

Sen. John Keenan hopes that will be included in the final version of the legislation.

"My main concern is that this does not include MAT for those incarcerated," Keenan said. "All three medications — buprenorphine, methadone and naltrexone — should be available."

Friedman said she wants to learn more about safe injection sites and other ideas to stem the overdose death rate.

"These are things that are new to people and we really need to look at that and be serious about using all the tools in the toolbox," she said.

Some provisions in the bill would be subject to appropriation and the Senate is expected to debate its spending plan later this month.